U.S. Pat. No. 5,358,469 describes an orthesis having a joint mechanism on which a rail is arranged on a first joint element and a rail is arranged on a second joint element. The securing to a limb, in particular to a leg, is effected by means of the rails. The joint mechanism has a common rotational axis about which the two joint elements pivot in relation to one another. The joint mechanism has associated therewith a spring which can bring about a preloading in the direction of flexion and/or extension in order to support a movement or to counteract it. The pivoting movement is restricted by means of a pin-shaped stop with a housing in which spring-loaded locking pins are arranged. Holes in which the locking pins engage are provided in a housing in order to define the extent of the pivoting movement. In order to adjust the stop position, the retaining pins are pressed into the housing and displaced to the desired bore.
U.S. Pat. No. 7,534,220 B2 describes an orthesis having two rails which are mounted so as to be rotatable side by side. A lower leg rail and an upper rail are arranged on a joint mechanism. Each rail is preferably fastened on the joint mechanism by means of rivets. An extension, which is produced from a rigid material, for example steel, and has a row of adjusting holes spaced apart from one another, can be fastened on each rail. As soon as the desired length adjustment has been performed, it is fixed by means of a screw-in button or a locking lever. Elevations, which indicate in a haptic manner the correct alignment of the rails with respect to one another, are provided in order to facilitate the aligning of the adjusting holes with respect to the locking elements.
The design of such a joint mechanism is costly, the adjustment of the stop position requires fine motor abilities and the structure is susceptible to contamination and water ingress.